10 Times The Joker Basically Defeated Himself
3. Joker Loses His Mind After Learning Batman's Identity - Batman #74 (1952)
In this story, The Crazy Crime Clown, the Joker pretends to be crazy so he can sent to an insane asylum. Why the Joker needs to convince anyone he is crazy is... anyone's guess, but anyway, Batman tells Robin that he believes the Joker was deliberately sent to the facility so he could steal a fortune from one of the inmates.
After Bruce Wayne infiltrates the institution by pretending to be an inmate, he tries to encourage the Joker to confess his scheme. However, the sinister clown deduces the inmate is Batman and has him locked in one of the padded cells. In a further twist, when the Joker returns to the cell, the Caped Crusader has unmasked himself, revealing he is Bruce Wayne.
As the Joker tries to process this revelation, an inmate who believes himself to be Batman appears behind him. This confuses the Joker so much, he can't tell what's real or not. He even questions whether he is the Joker!
With his perception of reality shattered, the Joker stops fighting, allowing Batman to have him arrested and transported to the state prison.